This invention relates to apparatus and methods for cooling electronic devices, such as, for example, fan trays having stator blades for improving the air flow performance of the fans mounted thereto.
Data processing units, such as routers, switches, servers, storage devices, and/or components included within a core switch fabric of a data center, include electronic devices (e.g., amplifiers, signal processors, optical transceivers or the like) that can generate heat during their operation. To increase the processing speed and/or processing capacity, some known data processing units include high power electronic devices, more densely packaged electronic devices and/or the like. Accordingly, some known data processing units include forced air cooling systems to prevent overheating of the electronic devices contained therein.
Such known data processing units can include, for example, one or more fan trays upon which fans and/or blowers are mounted. The fan trays can be mounted within the chassis (or frame) of the data processing unit, and can produce a pressurized air flow within the channels, ducts and/or air flow pathways of the chassis to cool the electronic devices. Such fan trays further facilitate the mounting and electrical connections used to operate the fans and/or blowers. For example, some known fan trays can be configured to be contained within a specific “bay” defined within the chassis. Such fan trays can be referred to as “rack mounted” or “rack mountable” fan trays.
The selection of the air flow device (e.g., the fan or blower) for cooling known data processing units can be based on a variety of constraints, including, for example, the desired flow rate and pressure of the air flow, the power requirements, the cost of the device and/or the size of the device. In view of these criteria, some known data processing units include axial air flow devices, which produce an air flow that is substantially parallel to the axis of rotation of the rotor (e.g., the blade, propeller or impeller). Axial air flow devices generally produce a higher airflow, albeit at lower pressures, than a similarly-sized centrifugal blower. In particular, some known data processing units include one or more tubeaxial fans mounted to a fan tray.
Known axial fans used for cooling data processing units, however, can be susceptible to flow pulsations, high noise emissions and/or operation at low pressure or low efficiency. Accordingly, some data processing units include axial fans mounted in series, dual-rotor axial fans or the like. Such axial fan configurations, however, result in increased size and/or cost. Moreover, such axial fan configurations are often configured for a specific chassis design, and are not easily used in multiple different designs.
Thus, a need exists for improved apparatus and methods for improving the efficiency and flexibility of cooling systems for data processing units.